Plastering machine



Oct. 5, 1937. E. P. GASSMAN ET AL PLASTERING MACHINE Filed March 3, 1956Patented Oct. 5, 1937 I y UNITED STATES PATENT OFFICE PLASTERING MACHINEEdward P. Gassman, Compton, and George J.

McCaughey, Los Angeles, Calif.; Madge E. Gassman administratrix of saidEdward P. Gassnian, deceased Application March 3, 1936, Serial No.66,854

14 Claims. (Cl. 72-130) This invention relates to a plastering machine,and the means for feeding in the ingredients of and while the machinemay be used for placing the plaster mix.

cement or plaster in any situation, it is intended Fig. is a verticalsection taken on the line particularly for facilitating the applicationof 5-5 of Fig. l, and further illustrating details 5 plaster to wallsand ceilings. of the plastering nozzle. 5

The general object of the invention is to pro- Fig. 6 is a verticalsection taken about on the vide a machine for this purpose, having meansline 6-i3 of Fig. 4 at the forward end of the feed for employing an airblast to carry the plaster screw, and particularly illustrating thedetails of through the hose to the plastering nozzle from the air nozzleand the worm head.

10 which the plasteris delivered onto the vertical Before proceeding toa moredetailed descrip- 1 Wall; and one of the objects of the inventionis t tion of the invention, it should be stated that in provide aconstruction, which will operate to subpracticing the invention, weprovide a barrel or stantially prevent any backward flow of the air y dr W t means Within the S o di in the barrel of the machine that carriesthe forward the plaster mix. The forward end of plaster into the hose.this barrel delivers to the flexible conduit, such 1:;

A further object of the invention is to conas a hose, which carries theplastering nozzle. At struct the machine so that the air nozzle can theforward end of the barrel we admit an air readily be adapted to heavy orlight materials stream flowing in the direction in which the employed toform the plaster mix. plaster mix is discharged from the barrel, andthis A further object of the invention is to proir is s in rry n h p rhr u h he 20 vide a machine of this kind in which the machine os and utf th p ast r nozzl Th f ed n will operate to mix the ingredients of theplaster means in the barrel is preferably in the form of a in anydesired proportions. feed screw, or worm, which has a tubular shaft Afurther object of the invention is to imthrou wh the a u r t fl ws. Inth 5 prove the general construction of machines of vicinity of theairnozzle, means is provided for this kind; also to improve theconstruction of the insurin that the air stream will not tend to flowforward end of the feed screw in the, vicinity of b k ward the r ar ndofh rr l, n w the air nozzle. provide a construction forward of the airnozzle,

Further objects of the invention will appear which facilitates theacceleration of the plaster 3 hereinafter. by the air blast as it passesinto the hose, and at They invention consists in the novel parts and thesame time, enables the air nozzle to be accescombination of parts to bedescribed hereinafter, sible to chan h s m w desired to adapt all ofwhich contribute to produce. an efficient the air blast to theparticular requirements of the plastering machine. plaster mix withwhich the machine is employed.

A preferred embodiment of the invention is, Although the machine iscapable of being used described in the following specification, whilethe for plastering with plaster that has already been broad scope of theinvention is pointed out in the mixed, in the present specification wehave deappended claims. scribed it as embodying mixing means, which Inthe drawing: will enable the ingredients of the plaster to be 40 Figure1 is a side elevation with certain parts mixed directly together in thebarrel into which 40 broken away, illustrating the complete apparatusthey are separately introduced; and the mechawith the hose and also thewatergconnections nism also enables the relative proportions of theleading to theplastering nozzle. ingredients of the plaster to bereadily altered as Fig. 2 is a rear elevation of the machine; that maybe desired.

is to say, sis-viewed from the left side of Fig. 1 Referring moreparticularly o the parts, I in- 45 but with the hose detached. This viewparticudicates the casing of the machine which is conlarly illustratesthe driving means for the agitastructed so as to support a cylinder orbarrel 2 tors in the cement and sand bins.

of elongated form, said barrel carrying means for Fig. 3 is a verticalsection taken on the line advancing the plaster 3 through the same, and

3-3 of Fig. 1, and further illustrating the genthis means is preferablyin the form of a feed 50 eral arrangement of the bins and the feedapscrew 4 in the form of a worm carrying a helical paratus. blade orthread 5. The feed screw 4 has a tu- Fig. 4 is a horizontal sectiontaken about on the bular shaft 6 that carries the blade 5, and at theline 4-4 of Fig. 1, and further illustrating details rear end of thisshaft 6 we introduce an air blast of the means for feeding the plasterinto the hose, through a swivel connection I, including 2. stuff- 55 ingbox 8 to'prevent escape of the air. This air blast is preferablyprovided from a fan 9 connected through the swivel connection by meansof suitable piping It. The forward end of the barrel 2 preferablyprojects beyond the forward end of the feed worm 4, said worm beingprovided with an air nozzle II, which may be in the form of a cap orplug screwed into the end of the bore l2 of the shaft of the feed screw.In some cases this nozzle may be a reducing nozzle, and provided with abore l3 of reduced diameter. Such a nozzle would be preferable where themachine is operating upon plaster of relatively light Weight.

It should be understood that the feed screw 4 is rotated in thedirection indicated by the arrow in Fig. 4, so that it will push theplaster along the inside of the barrel and past the air nozzle II, atwhich point the plaster comes under the influence of theair blastissuing from the air nozzle, and is carried through a delivery nozzlel4. This delivery nozzle is connected by a flexible conduit such as ahose IS, with a plastering nozzle l6, which will be described more indetail hereinafter. The delivery nozzle I4 is preferably removablymounted on the outer face of the casing I by means of removable boltsI'I so as to render the air nozzle accessible.

In order to insure that the air blast'will not tend to kick back intothe back of the barrel, we provide means just to the rear of the nozzlefor preventing this. This may be accomplished by decreasing the pitch ofthe blade 5 toward the front to cause the plaster to pack tighter atthis point, but in the present instance, this means consists of anintermediate helical blade |8 that we use at this point, which isdisposed preferably halfway between the successive coils or threads ofthe helical blade 5. In other words, at the forward end of the worm ithas a double thread; that is to say, it is a double worm. Furthermore,these two helical blades l8 and 5 are extended forwardly beyond the airnozzle so as to form a worm head l9 composed of these two blades; andthese two blades (or more blades if desired) are connected together bylongitudinal braces in the form of bars 20, so as to increase therigidity at this point. Furthermore, in order to facilitate theexpansion of the air into a forwardly moving cone as it issues from thenozzle II, we prefer to give the inner diameter of the blades 5 and I8at the head l9, an increasing diameter toward the delivery end of thebarrel. This is illustrated in Fig. 4.

The machine is preferably provided with means for mixing the plasterdirectly in the barrel 2. For this purpose we prefer to provide a duplexhopper 2| comprising a cement bin 2|c and a sand bin 2| s, and the lowerportions of these bins 2|c and 2|s deliver the cement and sandrespectively, into feed barrels 22 and 23, in each of which a feed screw24 or 25 is located. The shafts 26 of these feed screws projectoutwardly at the rear end of the casing, and are provided with sprocketwheels 21, and one of the shafts 26 is provided with a driving sprocketwheel 21 that is driven by a sprocket chain 28 off of a sprocket wheel29 rigidly mounted on the tubular shaft 6 of the worm 4. In order todrive the other shaft 26 from the one that carries the sprocket wheel21, both of the shafts 26 are provided with sprocket wheels 30 carryinga driving chain 3|. The runs of this chain straddle a tubular neck 32that extends out from the adiacent end of the casing, and against whichthe sprocket wheel 23 seats.

The tubular shaft 6 is provided with a driven gear wheel 33 driven by adriving pinion 34 on a countershaft 35 (see Fig. 4).

The feed screws 24 and 25 are driven in such a way that they will feedforward the cement and sand at a speed proportional to the proportion ofthese ingredients in the mix. For this purpose, if the feed screws 24and 25 have the same pitch, the sprockets 36 would have differentdiameters, and by choosing these diameters at different ratios, therelative proportions of the cement and sand in the mix can be regulatedas desired.

At the rear end of the barrel 22 a cement inlet opening 36 is providedfor admitting the cement into the rear end of the barrel 2; and on theopposite side of the barrel 2 a similar opening 31 is provided, which isa sand inlet. With this arrangement it will ,be evident that sand andcement in the proper proportions are delivered into the rear end of thebarrel 2. As this sand and cement is moved forwardly by the rotation ofthe worm 4, it is thoroughly mixed by suitable means such as mixerblades 38 that are preferably in the form of fins that project out fromthe wall of the tubular shaft 6. As illustrated, these mixer fins 38have the same pitch as the. screw blade 5, but if desired, they may havea reversed pitch so as to increase their mixing effect.

In order to insure that the cement and sand will feed down properly intotheir corresponding feed barrels, we provide rotary agitators 39 in theform of shafts 40 respectively, that pass through the bins and carryheaters 4|. These shafts project at the forward end of the are driven bysprocket chains 42 and 43, the latter of which is driven by a sprocketwheel 44 on the forward end of the corresponding feed screw (see Fig.2).

The plastering nozzle I6 is preferably formed with an elongated oval orrectangular mouth 45 (see Fig. 5) having an inner wall 46 with aplurality of small perforations 41, and this wall is surrounded by awater chamber or duct 48, which water chamber is provided with waterpreferably at two inlets 49 located at diagonally opposite corners ofthe nozzle (see Fig. 5). These inlets 49 are supplied with water fromthe forks 50 of the Y connection 5|, the shank of which is connectedthrough a valve 52 mounted on the nozzle with a water hose 53 pling 54.

It will be noted from Fig. 3, that the upper side of each feed barrel 22or 23 is provided with a longitudinal slot 55, through which the sanddown. In order to increase on the cement and sand as they pass throughthe mixing barrel 2, the blade 5 is preferably provided with a pluralityof notches 5a.

The forward end of the the outlet nozzle l4 clogging up.

The general mode of operation of the plastering machine will now bedescribed. The plaster is introduced into the rear end of the barrel 2.In the present instance the two ingredients, the cement and the sand,are forcedinto the barrel through their corresponding inlets by theircorresponding feed screws, and the mixture of the cement and sand isforced forwardly by the rotating feed screw or worm 4. The constructionof this worm is such that the plaster 3 tends to coil head projects into(see Fig. 4) and keeps it from machine, and

through a suitable couaoeassc become packed toward the forward end ofthe feed worm, and just to the rear of the air nozzle Ii. As the plasterpasses the air nozzle, the

absence of the central shaft 6 gives more room for the plaster, and itloosens up. At this point it encounters the air blast issuing from theair nozzle, which carries the plaster through the delivery nozzle H,which nozzle is preferably slightly tapered as shown in Fig. 4. This airblast carries the plaster through" the hose l5 to the plastering nozzle16 where it passes through the mouth 45, of the nozzle. As the plasterarrives at the mouth, it becomes mixedwtth small streams of water comingthrough the perforations 41. In using the plastering nozzle, it may beheld a slight distance from the wall, and the air blast drives the wetcement forward at a considerable velocity to spread itself evenly overthe wall. In using plasters of lighter weight, the nozzle It should havea considerably restricted reducing bore, as indicated at It in Fig. 6.This nozzle is accessible through the delivery end of the barrel 2, byremoving the delivery nozzle it.

By reason of the increasingly large inner diameter of the worm. head l9,opportunity is given for the air blast to expand as it issues from thenozzle ii, thereby increasing its effectiveness in 'carryingthe plasterforward into the delivery nozzle M.

It is understood that the embodiment of the invention described hereinis only one of the many embodiments this invention may take, and,

we do not wish to be limited in the practice of the invention, nor inthe claims, to the particular embodiment set forth;

What we claim is: 1. In a plastering machine, the combination of abarrel for carrying plaster, a feed screw mounted in the barrel, saidbarrel projecting beyond the end of the feed screw at the delivery end"of the barrel, means for rotating the feed screw to force the plasterthrough the end of the barrel, means for feeding plaster intothe barrelat the rear end of the feed screw, an air nozzle adjacent the forwardend of the feed screw, means for delivering a current of air to the saidnozzle through the feed screw for carrying the plaster through theforward end of the barrel, a plastering nozzle, flexible means forconducting the air stream and plaster to the last named nozzle, andmeans for mixing water with the plaster at the plastering nozzle.

2. In a plastering machine, the combination of a barrel for carryingplaster, a feed screw mounted in the barrel, said barrel projectingbeyond the end of the feed screw at the delivery and of the barrel,means for rotating the feed screw to force the plaster through the endof the barrel, means for forcibly feeding plaster into the barrel, anair nozzle adjacent the forward end of the feed screw, means fordelivering a current of air to the said noz'zle through the feed screwfor carrying the plaster through the forward end of the barrel, aplastering nozzle, flexible means for conducting the air stream andplaster to the last named nozzle, and means for mixing water with theplaster at the plastering nozzle, the forward end of said feed screwadjacent the air nozzle having means for substantially preventing airissuing from the air nozzle from blowing back toward the rear end of thefeed screw.

3. In a plastering machine, the combination of a barrel for carryingplaster, a feed screw mounted in the barrel, said barrel projectingbeyond the end of the feed screw at the delivery end of the barrel,means for force the plaster through the end of the barrel, an air nozzleadjacent the forward end of the feed screw, means for delivering acurrent of air to the said nozzle through the feed screw for carryingthe plaster through the forward end of the barrel, a plastering nozzleflexible means for conducting the air stream and plaster to the lastnamed nozzle, and means for mixing water with the plaster at theplastering nozzle, said feed screw consisting of a worm, said wormhaving an increased number of coils at the forward'end of the feed screwand just to the rear of the air nozzle for causing the plaster to packitself in the barrel, thereby substantially preventing the air currentfrom blowing back through the said barrel.

4. In a plastering machine, the combination of a barrel for carryingplaster, a feed screw mounted in the barrel, said barrel projectingbeyond the end of the feed screw at the delivery end of the barrel,means for rotating the feed screw to force the plaster through the endof the barrel, an air nozzle having its only outlet at the forward endof the feed screw, and delivering compressed air only longitudinally inline with the axis of the feed screw so that the interior ofthe barrelback of the nozzle is devoid of air under pressure, means for deliveringa current of air to the rear end of the feed screw for carrying theplaster through the forward end of the barrel, a plastering nozzle,flexible means for conducting the air stream and plaster to the lastnamed nozzle, means for mixing water-with the plaster at the plasteringnozzle, said feed screw being in the form of a worm with a helical bladeextending forwardly in the barrel beyond the air nozzle and forming acoil head beyond the air nozzle, and means for feeding the plaster intothe barrelat the rear of the same.

5. In a plastering machine, the combination of a barrel for carryingplaster, a feed screw mounted in the barrel, said barrel projectingbeyond the end of the feed screw at the delivery end of the barrel,means for rotating the feed screw to force the plaster through the endof the barrel, an air nozzle adjacent the forward end of the feed screw,means for deliveringa current of air to the said nozzle through the feedscrew for carrying the plaster through the forward end of the barrel,

a plastering nozzle, flexible means for conducting the air stream andplaster to the last named nozzle, and means for mixing water with theplaster at the plastering nozzle, said feed screw being in the form of aworm with a helical blade extending forwardly in the barrel beyond theair nozzle and forming a coil head beyond the air nozzle, the innerdiameter of said coil head being increased toward the delivery end ofthe barrel.

6. In a plastering machine, the combination of a barrel for carryingplasten-afeed screw mounted in the barrel, said barrel projecting beyondthe end of the feedscrew at the'delivery end of the barrel, means forrotating the feed screw to force the plaster through the end of thebarrel, an air nozzle adjacent the forward end of the feed screw, meansfor delivering a current of air the plaster at the plastering nozzle,said feed screw being in the form of a worm having a double helicalblade in the vicinity of the air nozzle, said rotating the feed screwtodouble blade projecting beyond the air nozzle and toward the deliveryend of the barrel to form a coil head, and braces connecting togetherthe blades forming the coil head.

'7. In a plastering machine, the combination of a barrel for carryingplaster, a feed screw mounted in the barrel, said barrel projectingbeyond the end of the feed screw at the delivery end of the barrel,means for rotating the feed screw to force the plaster through the endof the barrel, an air nozzle adjacent the forward end of the feed screw,said feed screw having a tubular shaft; and a blower mounted on themachine frame for blowing air through the bore of the tubular shaft andthrough the said nozzle for carrying plaster through the forward end ofthe barrel.

8. In a plastering machine, the combination of a barrel for carryingplaster, a feed screw mounted in the barrel, said barrel projectingbeyond the end of the feed screw at the delivery end of the barrel,means for rotating the feed screw to force the plaster through the endof the barrel, an air nozzle adjacent the forward end of the feed screw,means for delivering ingredients to form a. plaster mixture, through theside wall of the barrel toward the rear end thereof, means formed on thefeed screw for mix ng the ingredients as the same are moved forwardly bythe feed screw, said feed screw having a tubular shaft, means forblowing an air current through the said shaft and through the airnozzle, a hose leading from the delivery end of the barrel, a plasteringnozzle carried by the end of the hose, and means for mixing water withthe plaster at the plastering nozzle.

9. In a plastering machine, a plastering nozzle having a delivery mouthwith an annular wall surrounding the delivery mouth and having a waterduct therein extending along the outer side of said'wall, said wallhaving a plurality of perforations therethrough located adjacent the tipof the nozzle for admitting small streams of water into the said mouthas the plaster passes from the same, and means for delivering 'water tosaid duct.

10. In a plastering machine, the combination of a cement bin and a sandbin, a barrel extending under the same, a feed screw mounted in thebarrel, said barrel having a cement inlet and a sand inlet toward itsrear end, means for forcing cement from the cement bin through thecement inlet, and means for forcing sand from the sand bin through thesand inlet, said feed screw having a tubular shaft with means on theoutside of the shaft for mixing the sand and cement as the same aremoved forwardly by the feed screw,

means for delivering an air blast through the tubular feed screw, saidfeed screw having an air nozzle at its forward end, a hose connectedwith the forward end of the barrel, 9. plastering nozzle attached to theforward end of the hose, and means for delivering a plurality of smallstreams of water into the plaster at the plastering nozzle.

11. In a plastering machine, the combination of a cement bin and a sandbin, a barrel, a feed screw mounted in the barrel, said barrel having acement inlet and a sand inlet for delivering 'cemerit from the cementbin through the cement inlet, and means for delivering sand from thesand bin through the sand inlet, said feed screw having a tubular shaftand an air nozzle at the forward end of the barrel, means for deliveringan air blast through the tubular shaft and through the air nozzle, andmeans for mixing the sand and cement in the barrel before the same aredelivered by the feed screw to the forward end of the barrel.

12. In a machine for delivering a composition composed of differentingredients, the combination of a barrel, feed means within the barrelfor delivering the mixture from the same, said barrel having an inletfor one of the ingredients and an inlet for another ingredient, meansfor positively delivering a measured quantity of the differentingredients through their corresponding inlets into the interior of thebarrel, said feed means within the barrel having means for mixing theingredients delivered thereto.

13. In a machine for delivering a composition composed of differentingredients, the combination of a barrel, feed means within the barrelfor delivering the mixture from the same, said barrel having an inletfor one of the ingredients and an inlet for another ingredient, meansfor positively delivering a measured quantity of the differentingredients through their corresponding inlets into the interior of thebarrel, said feed means within the barrel having means for mixing theingredients delivered thereto, a hose attached at the forward end of thebarrel to receive the mixture from the same, and means for delivering anair blast through the said feed means and into the hose for carryingforward the mixture into the hose.

14. A machine constructed as described in claim 12, having means forvarying the ratio of the drive for the means that delivers the differentingredients into the barrel so as to enable the proportions of theingredients to be altered.

' EDWARD P. GASSMAN.

GEORGE J. McCAUGHEY.

